Question: Omar is 16 years older than Kevin. Omar and Kevin first met 3 years ago. Sixteen years ago, Omar was 3 times older than Kevin. How old is Omar now?
Explanation: We can use the given information to write down two equations that describe the ages of Omar and Kevin. Let Omar's current age be $o$ and Kevin's current age be $k$ The information in the first sentence can be expressed in the following equation: $o = k + 16$ Sixteen years ago, Omar was $o - 16$ years old, and Kevin was $k - 16$ years old. The information in the second sentence can be expressed in the following equation: $o - 16 = 3(k - 16)$ Now we have two independent equations, and we can solve for our two unknowns. Because we are looking for $o$ , it might be easiest to solve our first equation for $k$ and substitute it into our second equation. Solving our first equation for $k$ , we get: $k = o - 16$ . Substituting this into our second equation, we get the equation: $o - 16 = 3($ $(o - 16)$ $ -$ $ 16)$ which combines the information about $o$ from both of our original equations. Simplifying the right side of this equation, we get: $o - 16 = 3o - 96$ Solving for $o$ , we get: $2 o = 80$ $o = 40$.